The present invention generally relates to machines for exercising the muscles of the upper shoulder, deltoid muscles (delts), and laticimus dorcii muscles (lats). Numerous machines exist and have been known in the prior art for exercising the aforementioned parts of the human body. Such machines commonly utilize some sort of a movement arm which is moved by the body upon exertion of the muscles to be exercised and against a resistance, typically a weight stack or a free weight mounted on the movement arm. In the former, the movement arm is usually connected to the weight stack by an overhead cable and pulley system which increases the height of the machine and also introduces a certain amount of friction in the transmission of the drive thereby reducing efficiency. Machines of this type of the prior art also usually have parallel or coincident axes of rotation with the handles or user grips of such machines being unadjustable. This type of configuration can cause undue strain on the limbs and shoulder joints of the user and does not allow a full range of motion or muscular contraction.
Other types of exercise machines of the prior art use "free" weights as opposed to a weight stack. Free weights are typically interchangeable about a member protruding from the movement arm. An example of such a machine is shown in U.S. Pat. No. 5,171,198, Gary Jones. Although these "free" weight lateral raise machines eliminate the need for a cable or other transmission system between the movement arm and the weight stack, they have certain disadvantages in that it takes time and effort to change the weight each time a new repetition or exercise is to be performed. Also "free" weights are not always balanced and can subject the exerciser to jerky movements which can damage the muscles or lessen the efficiency of the exercise. Although the machine disclosed in the aforementioned U.S. Pat. No. 5,172,198 discloses angled pivot axes of the movement arms, the range of motion and muscular contraction is still limited.